Answer:
b- tense
Step-by-step explanation:
a- (incorrect) suspenseful means "arousing excited expectation or uncertainty about what may happen", we know there will be a storm and other important facts we need to know, which allows us to be certain about what is happening, so there is no excitement coming from uncertainty
b- (correct) we can sense the mood tensing when we read phrases like, "the rain pounded", "the crackling sound", "Please take cover! Take cover now!", etc.
c- (incorrect) there are no key words that lets us know that someone or something is angry.
d- (incorrect) technically, nothing is trying to threaten anyone, or anything, a storm is a natural disaster, and a natural event, which makes it hard to say something is trying to threaten someone, therefore we can't really say the mood is threatening (maybe saying that the people might feel like being threatened will be more closer to being correct).